Question

Find the perimeter of
(i) a triangle of sides 7.8 cm, 6.5 cm and 5.9 cm,
(ii) an equilateral triangle of side 9.4 cm,
(iii) an isosceles triangle with equal sides 8.5 cm each and third side 7 cm.

Answer 1

(i) Sides of the triangle are 7.8 cm, 6.5 cm and 5.9 cm.
Perimeter of the triangle = (First side + Second side + Third Side) cm
= (7.8 + 6.5 + 5.9) cm
= 20.2 cm

(ii) In an equilateral triangle, all sides are equal.
Length of each side of the triangle = 9.4 cm
$\therefore$ Perimeter of the triangle = (3 $\times$ Side) cm
= (3 $\times$ 9.4) cm
= 28.2 cm

(iii) Length of two equal sides = 8.5 cm
Length of the third side = 7 cm
$\therefore$ Perimeter of the triangle = {(2 $\times$ Equal sides) + Third side} cm
= {(2 $\times$ 8.5) + 7} cm
= 24 cm